Exhibit 21



SUBSIDIARY LIST



|                                                              |  |                       
|------------------------------------------------------------- |  | ----------------------
|NAME OF SUBSIDIARY                                            |  | STATE OF INCORPORATION
|Oglebay Norton Engineered Materials, Inc.                     |  | Ohio                  
|Oglebay Norton Industrial Sands, Inc.                         |  | California            
|Oglebay Norton Management Company                             |  | Ohio                  
|Oglebay Norton Marine Management Company, L.L.C.              |  | Delaware              
|Oglebay Norton Marine Services Company, L.L.C.                |  | Delaware              
|Oglebay Norton Minerals, Inc.                                 |  | Delaware              
|Oglebay Norton Specialty Minerals, Inc.                       |  | Ohio                  
|Oglebay Norton Terminals, Inc. d/b/a/ Cleveland Bulk Terminal |  | Ohio                  
|ON Coast Petroleum Company                                    |  | Texas                 
|ON Marine Services Company                                    |  | Delaware              
|ONCO Investment Company                                       |  | Delaware              
|ONCO WVA, Inc.                                                |  | West Virginia         
|ONMS Management Company, LLC                                  |  | Delaware              
|ONTEX, Inc.                                                   |  | Delaware              
|Saginaw Mining Company                                        |  | Ohio                  
|Texas Mining, LP                                              |  | Delaware              
|Global Stone Corporation                                      |  | Ohio                  
|Global Stone Chemstone Company                                |  | Delaware              
|Global Stone Filler Products Company                          |  | Delaware              
|Global Stone James River, Inc.                                |  | Delaware              
|Global Stone Management Company                               |  | Georgia               
|Global Stone PenRoc, LP                                       |  | Pennsylvania          
|Global Stone Portage, LLC                                     |  | Indiana               
|Global Stone St. Clair Inc.                                   |  | Delaware              
|Global Stone Tenn Luttrell Company                            |  | Delaware              
|GS Lime Company                                               |  | Georgia               
|GS PC Inc.                                                    |  | Delaware              
|Michigan Limestone Operations, Inc.                           |  | Michigan              
|Erie Sand and Gravel Company                                  |  | Pennsylvania          
|Erie Navigation Company                                       |  | Pennsylvania          
|Erie Steamship Company                                        |  | Delaware              
|Mountfort Terminal, Ltd.                                      |  | Pennsylvania